Characterization of Physiological and Biochemical Responses of Pineapple (Ananas comosus) to Exogenous Salicylic Acid under Chilling Stress

Abstract

Chilling stress is a major limitation to pineapple (Ananas comosus) production, affecting plant physiology, metabolic processes, and overall productivity in subtropical and marginal growing regions. This study characterizes the physiological and biochemical responses of pineapple to exogenous salicylic acid (SA) application under chilling stress conditions. Experimental treatments involved applying different concentrations of SA prior to exposure to low temperatures to evaluate its protective effects on plant performance. Key parameters assessed included chlorophyll content, electrolyte leakage, antioxidant enzyme activity, photosynthetic efficiency, and accumulation of osmolytes such as proline. Results indicated that SA application significantly enhanced chilling tolerance by stabilizing cellular membranes, reducing oxidative damage, and maintaining higher chlorophyll levels under stress conditions. Treated plants exhibited increased activity of antioxidant enzymes, including superoxide dismutase and catalase, which contributed to improved reactive oxygen species scavenging. Additionally, SA-treated plants showed better osmotic adjustment and maintained higher photosynthetic efficiency compared to untreated controls. Moderate SA concentrations provided the most effective protection, while excessive application did not yield additional benefits. The study highlights the potential of salicylic acid as a practical plant growth regulator for mitigating chilling stress in pineapple cultivation. While analytical techniques were used to assess physiological and biochemical responses, the primary emphasis remains on horticultural performance and stress management. These findings provide actionable insights for growers to enhance crop resilience, improve plant health, and sustain pineapple productivity under suboptimal temperature conditions.